Sad to say, since I like many of White lab's products, but wlp090 has definitely not proven itself a good yeast in my experience. It actually turned me down on everything it promised. It has low attenuation, not high, it produces a **** load of diacetyl, so it's not neutral and it ferments slowly not quickly! It might be a suitable yeast for some low gravity beers but as far as its advertised properties go, it definitely let me down. I did two beers with it, one low and one high gravity. Both ended up in stuck fermentation stinking like a diacetyl bomb. I was able to clean them up a bit by adding many packages of Fermentis US-05 to both beers and they turned out ok, eventually. Wasn't easy though.
Have I just been very unlucky with this? Does it matter? That's up to you but I want you to know that I am an experienced brewer, I follow pitching rates, I use good sanitation and I don't have anything against White labs' products all in all.
Yeast tends to mutate along the way which is why you can't reuse your yeast too many times. - So developing yeast can only be based upon letting it mutate. Did white labs this time let the base strain mutate to far? Is it a very unstable strain so that some tubes are good, while some are bad? I don't know. But I'm staying away from wlp090 from now on.
I've been brewing with WLP090 pretty much since it came out and haven't experienced anything like this. WLP090 is faster, more attenuative, and a better flocculator than chico-strain yeasts, in my experience. It is, however, a more finicky yeast to use.
Notice that the temperature optimal range is much narrower than most white labs products. Also: high flocculators tend to need a lot of oxygen (see: English yeasts like WLP002, 006 and 007), and this strain also likes a lot of oxygen- I've definitely gotten better performance out of it (faster ferments and flocs) since stepping up to pure O2 about a year ago, the only way to properly oxygenate your wort to the optimal 8ppm dO2.
If you have the ability to treat your yeast right, that is to say, pure O2, temperature control, and proper pitching rates, this yeast will outperform other clean american ale strains. I've never had anything like diacetyl come from any of the clean american yeasts, even with hot ferments that got away from me, low O2, and woefully inadequate pitch rates. I'm not sure what you'd have to do to those yeasts to get that result, but I wonder if it's not another flaw or ingredient throwing you off. Certain malts, in particular, can be a little off-putting to me, and I pick them up as a slight slickness or butter-nuttiness you might expect from diacetyl.
Not to shill for White Labs, but their QC is top notch- every batch gets multiple forced-ferment tests, which are subsequently analyzed on some pretty fancy-shmancy equipment before shipping and nothing goes out the door with high levels of any flaw compound. Having worked with yeast in the lab, I'd be willing to bet every strain is grown up from a single cell derived parent culture and is extremely stable generation to generation. Pro brewers typically take their yeast out as many as ten generations and can't typically pick up major differences on sensory panels.